NEW YORK (CNNMoney.com) -- A key measure of consumer confidence dropped significantly in February, to the lowest level in more nearly five years, amid mounting concerns about jobs and slowing business activity.

The New York-based Conference Board said Tuesday that its Consumer Confidence Index plummeted to 75, the lowest level since March 2003 (see below), from a revised 87.3 in January. Analysts had expected a decline to 82, according to Briefing.com.

The index rose slightly in December, but has now declined for a second-straight month. The 12.3 point monthly decline was the largest since September 2005.

Consumers claiming business conditions are "bad" rose to 21.8% from 20%, while those claiming business conditions are "good" decreased to 18.5% from 20.7%.

"With so few consumers expecting conditions to turnaround in the months ahead, the outlook for the economy continues to worsen and the risk of a recession continues to increase," said Lynn Franco, director of The Conference Board Consumer Research Center, in a statement.

The group's Expectations Index declined to 57.9 from 69.6, the lowest measure in more than 17 years.

The news cams after a government report showed wholesale prices, measured by the Producer Price Index (PPI), increased more than expected on rising food, energy, and drug prices. Retailers including Home Depot (HD, Fortune 500) and Target (TGT, Fortune 500) also released weak earnings reports earlier in the day.

"Prices are extremely strong from rising PPI numbers, consumers are shopping for discounts, and gasoline prices are rising," said Anika Khan, economist with Wachovia. "There have been lots of signs of economic uncertainty that have led to lower consumer confidence."

The Present Situation Index registered 100.6, down from 114.3, according to the Conference Board.

"The weakening in consumers' assessment of current conditions, fueled by a combination of less favorable business conditions and a sharp rise in the number of consumers saying jobs are hard to get, suggests that the pace of growth in early 2008 has slowed even further," said Franco.

Consumers expecting business conditions to worsen over the next six months increased to 21.4% from 16.3%, while those anticipating business conditions to improve decreased to 9.5% from 11.6%.

The percent of consumers expecting fewer jobs in the months ahead rose to 27.9% from 21.5%, while those anticipating more jobs declined to 9% from 10.5%.

The percentage of consumers saying jobs are "hard to get" rose to 23.8% from 20.6%, while those claiming jobs are "plentiful" fell to 20.6% from 23.8% in December.

"With the credit crunch and the housing market in turmoil, consumers are very worried about a weaker job market right now," said Khan.

Consumer confidence, which constitutes nearly three-quarters of all U.S. economic activity, has been closely watched by investors hoping to determine what direction the economy is headed.

An earlier version of this story gave an erroneous month and year for the lowest prior reading of the index. CNNMoney.com regrets the error.